Samples of normal tracheobronchial secretions will be isolated from lunas obtained at autopsy; age grouping and segregation of pathological specimens will be carried out. Complex carbohydrate components will be fractionated based on size, charge density, nature of carbohydrate moiety. Complete compositional data will be obtained for amino acids, neutral sugars, amino sugars, and sialic acids. Preliminary experiments establish the feasibility of obtaining metabolically labeled representative secretory products. Structural studies will be initiated on purified materials isolated as outlined above. Molecular weight, distribution of oligosaccharides on the protein core, mode of attachment of carbohydrate to protein, and nature of the saccharide fragments will be determined. Radiolabeled material obtained from culture studies will be employed as an analytical tool.